Endoprosthesis delivery system

ABSTRACT

Endoprothesis delivery systems, as well as related systems and methods are disclosed.

TECHNICAL FIELD

This invention relates to endoprosthesis delivery systems and relatedmethods.

BACKGROUND

Systems are known for delivering medical devices, such as stents, into abody lumen. Often, such systems include a proximal portion that remainsoutside the body during use and a distal portion that is disposed withinthe body during use. The proximal portion typically includes a handlethat is held by an operator of the system (e.g., a physician) duringuse, and the distal portion can include an outer member surrounding aninner member with a stent positioned therebetween. Generally, theoperator of the system positions the distal portion within the lumen ata desired location (e.g., so that the stent is adjacent an occlusion).The operator can then retract the outer member to allow the stent toengage the occlusion/lumen wall. Thereafter, the operator removes thedistal portion of the system from the lumen.

SUMMARY

In general, the invention relates to endoprosthesis delivery systems andrelated methods. The systems can be used, for example, to deliver amedical endoprosthesis (e.g., a stent) at a desired location within alumen of a subject (e.g., an artery of a human).

The systems generally include an inner member and an outer member atleast partially surrounding the inner member. The inner member and theouter member are configured so that an implantable medicalendoprosthesis (e.g., a stent) can be disposed therebetween. In general,the systems also include a device (e.g., a wire) that communicates witha portion of the outer member (e.g., a distal portion of the outermember) so that, when there is substantially no slack in the device, asthe device moves in a proximal direction, the portion of the outermember that communicates with the device also moves in the proximaldirection. The systems typically further include an adjustable stop thatcommunicates with the device so that, when there is slack in the device,as the adjustable stop is moved in the proximal direction, the amount ofslack in the device can be reduced.

In some embodiments, the adjustable stop includes a shaft that iscoupled to the inner member, and a member that is moveable along theouter surface of the shaft in the proximal direction.

In certain embodiments, the adjustable stop includes a shaft that iscoupled to the inner member, a first member and a second member. Theshaft has a threaded surface, and the first member (e.g., a nut) ismoveable in the proximal direction along the threads of the outersurface of the shaft. The second member is configured so that, as thefirst member moves in the proximal direction, the first member engagesthe second member.

In some embodiments, the implantable medical endoprosthesis deliverysystem can be designed to reduce (e.g., eliminate) slack in the devicethat is used to move the outer member in the proximal direction duringdeployment of the implantable medical endoprosthesis (e.g., stent). Thiscan enhance the control available to the user (e.g., surgeon) duringdeployment of the implantable medical endoprosthesis. Alternatively oradditionally, reducing (e.g., removing) slack in the device can allowfor more precise placement of the implantable medical endoprosthesis ata desired location (e.g., within a lumen of a subject).

Other features and advantages of the invention will be apparent from thedescription, drawings and claims.

DESCRIPTION OF DRAWINGS

FIGS. 1-3 are side views of a distal portion of an implantable medicalendoprosthesis delivery system during use.

FIG. 4A is a cross sectional view of an implantable medicalendoprosthesis delivery system.

FIG. 4B is a perspective view of area B of the implantable medicalendoprosthesis delivery system shown in FIG. 4A.

FIG. 5 is a side view of an implantable medical endoprosthesis deliverysystem.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

FIGS. 1-3 show a distal end of an implantable medical endoprosthesisdelivery system 10 that includes an inner member 12, an outer member 14surrounding inner member 12, and a stent 32 positioned between innermember 12 and outer member 14. The distal end of system 10 isdimensioned for insertion into a body lumen (e.g., an artery of ahuman). A guide wire 20 with a blunted end 22 is inserted into a bodylumen 24 by, for example, making an incision in the femoral artery, anddirecting guide wire 20 to a constricted site 26 of lumen 24 (e.g., anartery constricted with plaque) using, for example, fluoroscopy as aposition aid. After guide wire 20 has reached constricted site 26 ofbody lumen 24, inner member 12, stent 32 and outer member 14 are placedover the proximal end of guide wire 20. Inner member 12, stent 32 andouter member 14 are moved distally over guide wire 20 and positionedwithin lumen 24 so that stent 32 is adjacent constricted site 26 oflumen 24. Outer member 14 is moved proximally by pulling or retracting apull wire (as will be further described below), allowing stent 32 toexpand and engage constricted site 26. Outer member 14, inner member 12and guide wire 20 are removed from body lumen 24, leaving stent 32engaged with constricted site 26.

FIGS. 4A and 4B show an implantable medical endoprosthesis deliverysystem 100 including proximal and distal portions 110 and 120,respectively, that are connected to each other. Proximal portion 110includes a handle 125 including shafts 127A and 127B and an opening 129therebetween. Proximal portion 110 also includes a member 130 that canmove an along outer surfaces 122A and 122B of shafts 127A and 127B,respectively (see arrow). Member 130 includes a groove 132 dimensionedso that a wire 140 can fit within groove 132. The opposite end of wire140 is connected to a location 15 at a distal portion of outer member14. Member 130 has a threaded orifice 134 configured so that a set screw(not shown) can be fit into orifice 134. With this arrangement, when theset screw is not present in orifice 134, wire 140 is not coupled tomember 130. However, when the set screw is screwed into threaded orifice134, the set screw can securely contact wire 140 so that wire 140 iscoupled to member 130. Thus, when there is slack present in wire 140,the set screw can be positioned so that wire 140 is not coupled tomember 130. The slack in wire 140 can be removed by pulling wire 140 inthe proximal direction (e.g., using the operator's hands, using a pairof pliers) to position the proximal end of wire 140 further into groove132 without moving member 130 until the slack in wire 140 is removed.After the slack in wire 140 is removed, the set screw can besufficiently screwed into orifice 134 so that wire 140 is coupled tomember 130. When wire 140 and member 130 are coupled, moving member 130in the proximal direction over outer surfaces 122A and 122B of shafts127A and 127B, respectively, also moves wire 140 in the proximaldirection, which, in turn, moves outer member 14 in the proximaldirection, exposing stent 32 (not shown in FIGS. 4A and 4B) to expand toengage constricted site 26.

In some embodiments, member 130 is formed of a unitary piece of material(e.g., a plastic, such as a nylon, polyester, polyethylene orpolypropylene). For example, member 130 can have a unitary clamshellconfiguration. In certain embodiments, member 130 is formed of multiplepieces of material (e.g., two pieces of material, three pieces ofmaterial, four pieces of material, five pieces of material). Member 130can be formed, for example, by machining, injection molding, injectionco-molding, casting, extrusion and/or co-extrusion. In some embodiments(e.g., when it is desired to enhance the ability of member 130 to slidealong surfaces 122A and 122B of shafts 127A and 127B, respectively), theexposed surfaces of member 130 and/or shafts 127A and 127B can be formedof a material having a relatively low coefficient of friction (e.g., afluoropolymer or a silicone), and/or the exposed surfaces member 130and/or shafts 127A and 127B can be made of a material (e.g., a plastic)that includes a lubricious additive (e.g., a fluoropolymer, a silicone,an ultrahigh molecular weight polyethylene, an oil, or blends thereof).Examples of fluoropolymers include PTFE and FEP.

In some embodiments, member 130 and shafts 127A and 127B are configuredsuch that a certain minimum force is applied to member 130 before it canslide along outer surfaces 122A and 122B of shafts 127A and 127B,respectively. This can, for example, reduce the possibility ofinadvertent movement of member 130 or wire 140. Alternatively oradditionally, member 130 can include a trigger having a controlledrelease.

FIG. 5 shows a proximal portion 210 of an implantable medicalendoprosthesis delivery system 200. Proximal portion 210 includes ahandle 230 and a tube 240 that are coupled to each other. Proximalportion 210 also includes a shaft 250 having a thread surface 252, a nut260 and a member 270. One end of wire 140 is connected to member 270,and the opposite end of wire 140 is connected to a location at a distalportion of outer member 14 (not shown in FIG. 5).

Nut 260 and threaded surface 252 are configured so that nut 260 can berotated on threaded surface 252 to move nut 260 in the proximal anddistal directions. As nut 260 moves in the proximal direction, nut 260eventually engages a surface 272 of member 270. Member 270 is configuredto be able to slide along a surface 232 of handle 230 in the proximaland distal directions. Thus, when nut 260 is engaged with surface 272 ofmember 270, movement of nut 260 in the proximal direction results incorresponding movement of member 270 in the proximal direction.

With this arrangement, slack in wire 140 can be removed as follows. Nut260 is rotated so that nut 260 moves in the proximal direction to engagesurface 272 of member 270, and then nut 260 is further rotated tocontinue to move both nut 260 and member 270 in the proximal directionuntil the slack in wire 140 is removed. After removing the desiredamount of slack in wire 140, outer member 14 can be retracted to exposestent 32 (not shown in FIG. 5) by moving member 270 in the proximaldirection along surface 232. In some embodiments, it may be desirable tofix the relative positioning of nut 260 and member 270 relative to eachother (e.g., to reduce the possibility of slack being re-introduced intowire 140). In certain embodiments, nut 260 can be fixed in placerelative to member 270 by applying a suitable adhesive to nut 260 and/orthreads 252. Examples of adhesives include cyanoacrylate adhesives,including medical grade cyanoacrylate adhesives, such as Loctite® brandproducts available from Henkel Technologies (e.g., Assure™ 425 SurfaceCuring Threadlocker).

The pitch of threads 252 can be selected to achieve a desired degree ofcontrol when removing the slack from wire 140. Generally, the finer thepitch of threads 252, the finer control an operator, e.g., a physician,has over the amount of slack removed per turn of nut 84. In someembodiments, threaded surface 252 can have a pitch of at least about 6.5(e.g., at least about 13) turns per millimeter.

In general, shaft 250, nut 260 and member 270 are made of materials thatcompatible (e.g., so that rotation of nut 260 along surface 252 does notdamage nut 260 or shaft 250, so that engagement of nut 260 with surface252 does not damage nut 260 or member 270). In some embodiments, shaft250, nut 260 and/or member 270 are made of plastic (e.g., nylon,polyester, polyethylene or polypropylene).

In some embodiments (e.g., when it is desired to enhance the ability ofmember 270 to slide along surfaces 252 of shaft 250), member 270 and/orshaft 250 can be formed of a material having a relatively lowcoefficient of friction (e.g., a fluoropolymer or a silicone), and/ormember 130 and/or shaft 250 can be made of a material (e.g., a plastic)that includes a lubricious additive (e.g., a fluoropolymer, a silicone,an ultrahigh molecular weight polyethylene, an oil, or blends thereof).Examples of fluoropolymers include PTFE and FEP.

In general, stent 32 is a self-expanding stent. Examples of materialsfrom which stent 32 can be include shape memory materials, such asnitinol, silver-cadmium (Ag—Cd), gold-cadmium (Au—Cd), gold-copper-zinc(Au—Cu—Zn), copper-aluminum-nickel (Cu—Al—Ni), copper-gold-zinc(Cu—Au—Zn), copper-zinc/(Cu—Zn), copper-zinc-aluminum (Cu—Zn—Al),copper-zinc-tin (Cu—Zn—Sn), copper-zinc-xenon (Cu—Zn—Xe), iron beryllium(Fe₃Be), iron platinum (Fe₃Pt), indium-thallium (In—Tl), iron-manganese(Fe—Mn), nickel-titanium-vanadium (Ni—Ti—V), iron-nickel-titanium-cobalt(Fe—Ni—Ti—Co) and copper-tin (Cu—Sn). For yet additional shape memoryalloys, see, for example, Schetsky, L. McDonald, “Shape Memory Alloys”,Encyclopedia of Chemical Technology (3rd ed.), John Wiley & Sons, 1982,vol. 20. pp. 726-736.

Inner member 12 and outer member 14 are generally made of polymericmaterials. Examples of polymeric materials include polyether-blockco-polyamide polymers (e.g., PEBAX®), copolyester elastomers (e.g.,Arnitel® copolyester elastomers), thermoplastic polyester elastomers(e.g., Hytrel®), thermoplastic polyurethane elastomers (e.g.,Pellethane™), polyeolefins (e.g., Marlex® polyethylene, Marlex®polypropylene), high-density polyethylene (HDPE), low-densitypolyethylene (LDPE), polyamides (e.g., Vestamid®), and combinations ofthese materials. In certain embodiments (e.g., when it is desirable toreduce the force used to retract outer member 14), outer member 14and/or inner member 12 can be made of a material having a relatively lowcoefficient of friction (e.g., a fluoropolymer or a silicone). Examplesof fluoropolymers include PTFE and FEP. Alternatively or additionally,outer member 14 and/or inner member 12 can be made of a material thatincludes a lubricious additive (e.g., a fluoropolymer, a silicone, anultrahigh molecular weight polyethylene, an oil, or blends thereof).

Wire 140 is typically made of a material having the appropriate level ofstrength and flexibility. Examples of materials from which wire 140 canbe made include stainless steel, high modulus, oriented thermoplasticmaterials (e.g., fluoropolymers, nylons) and/or nitinol. Examples offluoropolymers include PTFE and FEP.

While certain embodiments have been described, other embodiments arepossible.

As an example, while embodiments have been described in which a setscrew is used in the system, more generally any fastening device ormechanism can be used. For example, clamps can be used. Alternatively oradditionally, crimping, snap fitting and/or adhesive materials can beused.

As another example, in certain embodiments, member 270 can have athreaded orifice/set screw arrangement as described above with respectto member 130. This can, for example, allow for additional flexibilityand/or control in removing slack from wire 140.

As a further example, in some embodiments, an implantable medicalendoprosthesis system can include a strain relief (e.g. located at adistal portion of the handle).

As an additional example, while embodiments have been described in whicha stent is contained in the system, more generally the systems cancontain any implantable medical endoprosthesis. Examples of implantablemedical endoprosthesis include stent-grafts and filters (e.g., arterialfilters, venus filters).

As another example, while embodiments have been described in which awire is present, more generally any device can be used that is capablecoupling the adjustable stop with a portion (e.g., a distal portion) ofouter member 14 so that, when there is substantially no slack in thedevice, as the device moves in the proximal direction the portion ofouter member 14 also moves in the proximal direction. Examples of suchdevices include vascular coils (e.g., vascular coils designed for usefor aneurysms).

Other embodiments are in the claims.

1. A medical endoprosthesis delivery system, comprising: an innermember; an outer member at least partially surrounding the inner member,the inner member and the outer member being configured so that animplantable medical endoprosthesis can be disposed therebetween; acoupling device coupled to a portion of the outer member so that, whenthere is substantially no slack in the coupling device, as the couplingdevice moves in a proximal direction the portion of the outer membermoves in the proximal direction; and an adjustable stop coupled to thecoupling device so that, when there is slack in the coupling device, asthe adjustable stop is moved in the proximal direction, the amount ofslack in the coupling device can be reduced.
 2. The system of claim 1,wherein the adjustable stop comprises: a shaft coupled to the innermember, the shaft having an outer surface; and a member that is moveablealong the outer surface of the shaft in the proximal direction.
 3. Thesystem of claim 2, wherein the member includes an orifice configured toreceive a fastening device.
 4. The system of claim 3, further comprisingthe fastening device in the orifice of the member.
 5. The system ofclaim 4, wherein the fastening device has a first position in which, asthe member moves in the proximal direction along the outer surface ofthe shaft, the coupling device moves in the proximal direction, and asecond position in which, as the member moves in the proximal directionalong the outer surface of the shaft, the coupling device does not movein the proximal direction.
 6. The system of claim 4, wherein thefastening device is a set screw.
 7. The system of claim 4, wherein thefastening device comprises one or more elements selected from the groupconsisting of clamping devices, crimping devices, snap fitting devicesand adhesive materials.
 8. The system of claim 2, wherein the member isformed of a unitary piece of material.
 9. The system of claim 2, whereinthe member is formed of multiple pieces of material.
 10. The system ofclaim 2, wherein a portion of the coupling device is disposed within themember.
 11. The system of claim 1, wherein the coupling device is awire.
 12. The system of claim 1, wherein the adjustable stop comprises:a shaft coupled to the inner member, the shaft having a threadedsurface; a first member that is moveable in the proximal direction alongthe threads of the outer surface of the shaft; and a second memberconfigured so that, as the first member moves in the proximal direction,the first member engages the second member.
 13. The system of claim 12,wherein, when the first member is engaged with the second member, as thefirst member moves in the proximal direction, the second member moves inthe proximal direction.
 14. The system of claim 12, wherein the secondmember is coupled to the coupling device so that, as the second membermoves in the proximal direction, the coupling device moves in theproximal direction.
 15. The system of claim 12, wherein the first memberis a nut.
 16. The system of claim 12, wherein the threaded outer surfaceof the shaft has a pitch of at least about 6.5 turns per millimeter. 17.The system of claim 1, wherein the implantable medical endoprosthesiscapable of being disposed between the inner member and the outer memberis a stent, a stent-graft, or a vena cava filter.
 18. The system ofclaim 1, wherein the implantable medical endoprosthesis capable of beingdisposed between the inner member and the outer member is aself-expanding medical endoprosthesis.
 19. A medical endoprosthesisdelivery system, comprising: an inner member; an outer member at leastpartially surrounding the inner member, the inner member and the outermember being configured so that an implantable medical endoprosthesiscan be disposed therebetween; a wire coupled to a portion of the outermember so that, when there is substantially no slack in the wire, as thewire moves in a proximal direction the portion of the outer member movesin the proximal direction; and an adjustable stop coupled to the wire sothat, when there is slack in the wire, as the adjustable stop is movedin the proximal direction, the amount of slack in the wire can bereduced, the adjustable stop comprising: a shaft coupled to the innermember, the shaft having an outer surface; and a member that is moveablealong the outer surface of the shaft in the proximal direction, themember including an orifice; and a set screw in the orifice of themember, the set screw having a first position in which, as the membermoves in the proximal direction along the outer surface of the shaft,the wire moves in the proximal direction, and a second position inwhich, as the member moves in the proximal direction along the outersurface of the shaft, the wire does not move in the proximal direction.20. A medical endoprosthesis delivery system, comprising: an innermember; an outer member at least partially surrounding the inner member,the inner member and the outer member being configured so that animplantable medical endoprosthesis can be disposed therebetween; a wirecoupled to a portion of the outer member so that, when there issubstantially no slack in the wire, as the wire moves in a proximaldirection the portion of the outer member moves in the proximaldirection; and an adjustable stop coupled to the wire so that, whenthere is slack in the wire, as the adjustable stop is moved in theproximal direction, the amount of slack in the wire can be reduced, theadjustable stop comprising: a shaft coupled to the inner member, theshaft having a threaded surface; a nut that is moveable in the proximaldirection along the threads of the outer surface of the shaft; and asecond member configured so that, as the nut moves in the proximaldirection, the nut engages the second member, wherein: when the nut isengaged with the second member, as the nut moves in the proximaldirection, the second member moves in the proximal direction; and thesecond member is coupled to the wire so that, as the second member movesin the proximal direction, the wire moves in the proximal direction. 21.A method of treating a lumen within a patient, the method comprising:inserting the system of claim 1 into the lumen.
 22. A method of treatinga lumen within a patient, the method comprising: inserting the system ofclaim 19 into the lumen.
 23. A method of treating a lumen within apatient, the method comprising: inserting the system of claim 20 intothe lumen.